In underground mining, the minerals which are won by means of mining machines such as, for example, mining ploughs or drum-cutter loaders, in particular coal, but also ores, potash and the like, are transported by means of scraper chain conveyors, which are made up of a multiplicity of hinge-connected conveyor pans. Since the won material is almost always transported in the top strand, since debris formations can also be permitted there, the top strand is generally prone to substantially greater wear than the bottom strand. It has therefore long been known to use in the conveyor pan a changeable trough, which after excessive wear can be exchanged for a new changeable trough or repaired so that the working life of the substructure can be fully utilized.
The changeable trough can be fastened to the conveyor pan differently, for example by means of clamps secured to the substructure by screw bolts, the clamps applying a clamping force in order to pretension the changeable trough against the substructure so as to prevent vibrations of the changeable trough even in continuous running, which vibrations can cause additional noise loads or an impaired passage of the scrapers of the scraper chain.